When drawing you often need to draw a detail of a piece with another scale. Could you imagine a tool with which you define an area in which all dimensions (except angles) are multiplied or divided by the scale factor.

You draw a mecanical piece with the original dimensions (1:1). You use the dimensions and the measures represented are correct.
Now your mecanical piece is a little bit complicated an you want to show a detail or part of your drawing in another scale, let's say you copy a part, enlarge it by factor 4. So far there is still no problem.
As soon as you want to represent the mesures by dimensioning, this part all the values are wrong because they are multiplied by four, of course for the system there is no problem because it doesn't know that you only want to show a detail in another scale BUT with the original measures.
Actually I see no other solution as to manually edit all values and correct them.